The present invention relates in general to a wireless mobile telephone communication system, and more particularly, to an interface operative for coupling a wireless telephone unit to a mobile telephone unit, for example, of the cellular type, to provide the user with the capability of establishing two-way communications with a base station through the mobile telephone unit when using the wireless telephone unit at a location remote from the mobile telephone unit. Still more particularly, the present invention relates to a conventional wireless telephone unit having a wireless handset coupled to a conventional cellular mobile telephone unit through an interface so as to provide the user with the freedom to establish two-way communications with the base station independent of the user's proximity to the mobile telephone unit.
Mobile telephone units have become increasingly popular for both business and personal use. To this end, mobile telephone units have been installed in cars, limousines, trucks, boats and even farming equipment such as tractors and the like. One disadvantage of the mobile telephone unit is the provision of a wired handset which necessitates that the user remain within the vehicle for communicating with a base station, i.e., to establish two-way communications by transmitting and receiving incoming and outgoing telephone calls.
Often, the need arises for the user to leave the vehicle unattended, while at the same time, being reachable at the time of an incoming telephone call to the mobile telephone unit. To this end, there is known from U.S. Pat. No. 3,811,012 and Japanese Patent Publication Nos. 57-53161 and 56-12141 a paging system adapted for such purpose. The user, upon leaving the proximity of the mobile telephone unit, carries a paging unit which beeps or provides such other indication that a telephone call has been received by the mobile telephone unit. Upon being paged, the user must retreat from his present position to the mobile telephone unit in order to receive the incoming telephone call. In order to avoid this disadvantage, there is known from Japanese Patent Publication No. 56-44232 a remote paging unit which relays to the caller a telephone number of a local telephone where the user is remotely situated. This known system, however, has little utility when the user is in an area where access to a local telephone is not possible. Accordingly, it can be appreciated that there is an unsolved need for a wireless mobile telephone communication system which allows the user to communicate with the base station independent of the user's proximity to the mobile telephone unit or a local telephone.